In 2006, at a property in Halifax, Bristow, 48, raped a girl aged “11 or 12” while Peters, 72, took photographs.

Police recovered pictures from Peters’ home that depicted him laying naked with a 13 year-old-boy. Further indecent photographs were found at his house and he alluded to other offences when questioned by police.

Bristow admitted a further offence of sexual assault on a young girl.

Jude Jonathan Rose, sentencing, said: “There is not a single right-thinking, decent person who would feel anything but utter revulsion at the details of the indictment.

“You have entered into a relationship. You became partners in paedophilic abuse.

“You have descended to real depths of depravity.

“You have not thought at all about how much more terrifying and unpleasant it would be to be sexually abused by two grown men acting together.”

Judge Rose said he was only able to sentence the pair for the crimes listed in court, despite Peters alluding to other offences against children.

He said: “Michael Peters, you have committed sexual offences against children repeatedly for almost 50 years and, again, these right-thinking people will wish me to put you in prison to die for that would be regarded by the public as the only appropriate punishment for the years of abuse by you.

“You, Bristow, raped her. It was for your sexual pleasure and the pleasure of your partner. The public must understand I am sentencing you for the offences on this indictment that you have pleaded guilty to.”

The court heard Bristow last committed an offence in 2009 but this his first conviction for sexual abuse.

Peters was convicted of outraging public decency in 1971 when he followed two boys in his car and passed them a note with an indecent message.

Michael Collins, mitigating for Bristow, said: “He is remorseful for his conduct. He has suicidal thoughts.

“He has no relevant previous convictions and there has been no offending of this nature since 2006.”

Nicholas Clarke, mitigating for Peters, said: “The candour he has expressed is almost unprecedented, especially with regard to the fact he has admitted far and above what appears before your honour.

“He has spent most of his life as useful, working man but in the shadows he is committing offences as a predatory paedophile.”

Bristow was jailed for eight and a half years, and Peters for six. Both must sign the sex offenders register for life and are subject to a sexual harm prevention order.

Detective Inspector Allan Raw, of Calderdale District Police’s Safeguarding Department, said: “West Yorkshire Police are committed to investigating all reports of sexual abuse, whether they have occurred historically or more recently.

“We are dedicated in our pursuit of protecting the most vulnerable and supporting those who have shown the immense courage in coming forward. We have specialist units of officers who not only investigate all reports of this matter but proactively seek to prosecute those who prey on the young and vulnerable.

“This particular investigation demonstrates the lengths that West Yorkshire Police and colleagues in other forces, will go to, to ensure the safeguarding of our most vulnerable members of society. This case shows that we are committed to seeking justice for victims, will strive to obtain all available evidence, to ensure a positive outcome, not only for the victims in this case but for our communities.

“We would like to acknowledge the tremendous bravery and courage of those victim who have provided their evidence in this case and hope that the result obtained today, can assist them in moving on with their lives.

“This investigation has been carried out jointly with other Forces from around the UK and due to our close working relationship and innovative methods of investigation, we have ensured that two dangerous offenders have been brought to justice.

“There may still be victims in both the West Yorkshire and Surrey areas, who Peters and Bristow sexually abused, but who we have not identified. I would encourage those victims to speak to the police by contacting their local Police Force via the non-emergency telephone number 101. Their allegations will be treated sensitively and seriously.”